Elder Joseph the Hesychast. "Monastic wisdom". From letter 3.
And so, my child, force yourself from the beginning to enter the narrow gate, because only it leads to the spaciousness of paradise. Cut off your own will every day and hour, and seek no other path besides this one. This is the path that the feet of the Holy Fathers trod. Reveal your path unto the Lord and He will guide you, too. Reveal your thoughts to your elder, and he will heal you. Never hide a thought, because the devil conceals his cunning within it: as soon as you confess it he disappears. Do not reveal another person’s fault to justify yourself, because at once grace, which had covered you until that point, will reveal your own faults. The more you cover your brother with love, the more grace warms you and guards you from the false accusation of men.
As for the other brother you mentioned, it seems that he has some unconfessed sins, because he is ashamed to tell them to the elder. And this is why that temptation takes place. But he must correct this improper behavior, for without frank confession, one cannot be purified. It is a shame to be ridiculed by the demons. Deep down his ego is hiding. May the Lord enlighten him to come to his senses. And you should pray and love him as well as everyone; yet guard yourself from all.